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Path-integral study of positronium decay in xenon
1Southern University, Baton Rouge, Louisiana 70126, USA.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|December 12, 2001
Summary
We studied positronium in xenon gas using quantum simulations. Positronium remains self-trapped even at high densities, challenging previous assumptions about its behavior.
Area of Science:
- Quantum physics
- Materials science
- Chemical physics
Background:
- Quantum particles in fluids present unique physical challenges.
- Understanding positronium behavior in dense media is crucial for materials science.
Purpose of the Study:
- To investigate the properties of a quantum particle (positronium) in a classical Lennard-Jones fluid (xenon).
- To model thermalized positronium behavior above the xenon critical temperature.
- To compute the annihilation rate as a function of density.
Main Methods:
- Path-integral Monte Carlo simulations were employed.
- The quantum particle's mass was set to 2m(e).
- Potential parameters mimicked xenon interactions.
Main Results:
- Local fluid distortions around the quantum particle were analyzed.
- Annihilation rates were calculated on two isotherms.
- Results showed good agreement with experimental data below the critical point density.
Conclusions:
- Positronium remains in a self-trapped state at densities exceeding twice the critical point.
- This finding contradicts previous scientific understanding of positronium behavior in dense fluids.